1. Field of the Invention
This invention is concerned with the management of a human airway in order to control respiration. More particularly, the invention concerns a device that brings an airway tube reliably and safely into communication with the laryngeal opening, the upper end of the trachea, which is the breathing passageway that leads to the lungs. The device seats in the throat immediately adjacent the laryngeal opening, tensions and erects the laryngeal opening, and seals with it to provide a channel through the airway tube for artificial ventilation of the lungs. In particular, the invention concerns a laryngeal airway device that can be coupled to an introducer and guided to this position through the throat. For this purpose a tracking introducer is provided.
The invention also concerns a laryngeal blade used to access the laryngeal anatomy in order to support access to the laryngeal opening by an airway device.
Another concern of interest in consideration of the invention is engagement and control of the epiglottis as an aid in gaining access to the laryngeal anatomy.
2. Description of the Related Art
An airway device facilitates ventilation of the lungs of a person. The purpose of such a device is to provide an air pathway from an external air source, through the mouth, throat, and trachea, to the lungs. Additionally, some airway devices provide a seal with the throat of a person, which allows positive pressure ventilation and which may also prevent the leakage of stomach contents into the trachea (aspiration).
It is useful to divide airway devices into two categories: those that pass through the vocal chords and are commonly referred to as "tracheal tubes", and those that lodge in the throat, above the vocal chords, and are commonly referred to as "airways". We shall limit "airway" to refer to a device that provides a fluid pathway from outside the mouth of a person to a location above the vocal chords.
In the variety of airway devices that are available, some merely support the tissue of the pharynx (throat), particularly the tongue, creating a passageway so that air can pass by and into the pharyngeal space toward the laryngeal opening, which is the opening into the voice box. Other airway devices include a tube that provides an air channel to a location near the laryngeal opening. Still other airway devices add a sealing means to the distal end of the tube in order to provide some degree of sealing between the tube and the airway of the person.
A laryngeal mask is an example of a sealing airway device. U.S. Pat. Nos. 4,509,514; 4,995,388; and 5,355,879 are descriptive of a laryngeal mask. A laryngeal mask includes an inflatable doughnut-shaped balloon which, when inflated, circles the laryngeal opening and creates a fluid seal between the outside of the inflated balloon and the tissues in the pharyngeal structures of the throat that surround the larynx.
Another sealing airway device, described in U.S. Pat. No. 5,513,627, includes an inflatable balloon fixed on the distal end of a tracheal tube that is inserted into and inflated within the trachea, forming a seal against the interior walls of the trachea.
In the first three cross-referenced patent applications, all assigned to the assignee of this application and incorporated in their entirety by this reference, a sealing member is mounted near the distal end of an airway tube to seal directly with the rim of the laryngeal opening, portions of the epiglottis, and the sidewalls of the larynx. This unique airway creates a fluid seal directly with the larynx.
Accurate placement of an airway device can be a very difficult task for the clinician and a traumatic event for the patient. When a patient is under anesthesia, or has lost consciousness for other reasons, the tongue and tissues of the throat relax and fall back, effectively obstructing the flow air from the mouth or nose to the laryngeal opening. This same relaxation of the tongue makes it difficult to pass an airway device along the back of the tongue, into the throat. Frequently, the clinician's fingers must be inserted into the patient's mouth to displace the tongue or push the airway device around the corner at the posterior pharynx. Furthermore, the highly variable and extremely flexible anatomy surrounding the larynx make accurate positioning of an airway device very difficult. In particular, the epiglottis must be correctly positioned in order to introduce and seat an airway device that effectively seals against the laryngeal opening. An epiglottis that covers the larynx will prevent a proper seal. Finally, the mucosal tissues lining the mouth, throat, and larynx are very fragile. Devices that are inserted blindly frequently scrape these tissues causing bleeding, sore throats, and throat infections.
Accordingly there is need for easy guidance of an airway device through the mouth and throat that will result in accurate positioning of the device with respect to the larynx.
Accordingly, there is a need for a device that will provide access to the laryngeal anatomy for the purpose of airway management.
Accordingly, there is a need for a laryngeal access device with provision for engagement and control of the epiglottis.